As known, a keyboard device can provide an intuitional feedback-imparting interface for allowing the user to input signals to an electronic device in a simple manner. Even if most electronic devices are equipped with touch screens and virtual keyboards are shown on the touch screens for allowing users to input signals, physical keyboard are still frequently used by most users because the hand feel of touching the touch screen is lower than the tactile feedback of pressing the physical keyboard and the possibility of erroneously touching other keys of the touch screen is very high.
FIG. 1 is a schematic view illustrating a conventional keyboard device. As shown in FIG. 1, the conventional keyboard device 10 comprises plural keys 11, a circuit board 12 and a base plate 13. Each of the plural keys 11 comprises a keycap 111, a scissors member 112 and a rubbery elastomer 113. The keys 11 are disposed on the circuit board 12. The circuit board 12 is disposed on the base plate 13. In particular, the scissors member 112 is arranged between the keycap 111 and the rubbery elastomer 113 for connecting the keycap 111 and the base plate 13. The rubbery elastomer 113 is disposed on the circuit board 12 and located under the scissors member 112 for returning the keycap 111 to the original position. When the key 11 is depressed, the keycap 111 is moved downwardly to press the rubbery elastomer 113 so as to result in deformation of the rubbery elastomer 113. At the same time, the circuit board 12 is pressed by the rubbery elastomer 113 so as to generate a key signal. When the key 11 is no longer depressed, the rubbery elastomer 113 is restored to the original shape. Consequently, the keycap 111 is moved upwardly in the direction away from the base plate 13.
As mentioned above, the keycaps 111 are fixed on the base plate 13 through the scissors member 112 of the keyboard device 10, and the rubbery elastomer 113 of the keyboard device 10 provides the hand feed of pressing the key 11 to the user. Moreover, when the key 11 is no longer depressed by the user, the rubbery elastomer 113 can allow the keycap 111 of the key 11 to be returned to the original position. However, since the combination of the scissors member 112 and the rubbery elastomer 113 has certain height and volume, the overall height of the keyboard device 10 is increased.
In other words, it is an important issue to provide a keyboard device with slimness and hand feel. Therefore, there is a need of providing an improved keyboard device in order to overcome the above drawbacks.